A phosphor is used broadly in various fields. For example, the phosphor is used as a phosphor for a lighting device such as a fluorescent lamp, a phosphor for a display device such as a PDP, and a phosphor for an x-ray pickup tube. For example, in a color display device, three-color phosphors of red, blue and green are used in general, and white can be obtained by combining fluorescence from the three-color phosphors. In particular, because the green phosphor is an important phosphor to determine luminance of white, an offer of a green phosphor that generates fluorescence having high luminance and high color purity is desired.
(Ba, Mn)Al12O19, (Y, Tb)BO3 and Zn2SiO4: Mn are well known as conventional green phosphors. Further, as a blue phosphor, a phosphor represented by BaMgAl10O17: Eu2+ (a part of Mg is substituted with Ca, Cu, Zn, Pb, Cd, Mg or Sn) is also known (Japanese Unexamined Patent Application No. 2002-173677: Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Application No. 2002-173677